Gear Manufacturer Cuts Costs By Reclaiming Used Tools

This gear manufacturer needed to reduce high costs resulting from replacing dull drill bits or sending them out for sharpening. With the XT3000 Xpandable tool sharpener from Darex, the shop has done just that. In addition, the device allows the company to custom-sharpen drills for specific jobs.

Case Study
From:
5/21/2008
Modern Machine Shop

Click Image to Enlarge

The Darex machine has not only provided the company with cost savings, but also eliminated quality concerns associated with sending drills out of the shop for sharpening.

The drill sharpener is designed so that shop personnel can intuitively understand how to operate it. Most can begin using the device almost immediately with very little training.

Machine operators can custom-sharpen drills by changing point angles or styles for specific jobs.

Times have changed in the world of manufacturing, says Tim Wood,
president of Dalton Gear. “With the current trends and continued
demands for tight tolerances that our customers place on us, precision
tools are becoming more and more common,” he says.

However, precision tools are expensive, and replacing or sharpening worn tools can further drive up costs.

This
was the case at Dalton, where worn drill bits that needed to be either
replaced or sent off-site for sharpening significantly reduced profits.
To better control its expenses, the shop purchased the XT3000 Xpandable
tool sharpener from Darex.
Thanks to the device’s high precision, ease of use and ability to
custom-sharpen tools to operator specifications, the shop has been able
to bring worn drills to like-new condition in-house. Tooling costs are
down, and the shop has yet to order new drills since purchasing the
device.

Founded more than 50 years ago in Minneapolis, Minnesota, Dalton Gear
markets its products in the United States, Canada and Europe. In
addition to spur, helical, bevel and worm gears, the company
manufactures sprockets, shear-pin couplings, timing-belt pulleys,
right-angle gearboxes, drive shafts, transmission shafts and idlers.
Manufacturing these components requires various drilling and tapping
operations, for which the company’s 35 employees use various CNC
machines, mills and drill presses. Materials include mild steels,
alloy, brass, bronze, aluminum, stainless steel, cast iron and
heat-treated steel. Most of the company’s drills are jobber length, and
the most common have a 118-degree point configuration.

According to purchasing manager Scott Holler, Dalton had been
experiencing “out-of-control” costs associated with the purchasing and
sharpening of drill bits. In fact, a cost analysis revealed that the
company had purchased at least $13,000 in new drill bits during a
period of several years. After the bits became worn, most sat
accumulating dust. Others were sent out for sharpening, if that was
economical compared to the cost of buying new tools.

With
the XT3000, however, the company has sharpened many of the old drill
bits that had accumulated over the years and recovered its initial
outlay. “We had about two and a half plastic bins full of dull drills
waiting to be sharpened,” Mr. Holler says. “We converted a storage room
in our shop just for sharpening drills, with a workbench and shelving
bins for the sharpened bits.”

The base XT3000 unit
sharpens standard and split-point drill bits at angles ranging from 118
to 150 degrees. It includes two adjustable, stainless steel chucks that
accommodate drill bits with diameters ranging from 1/8 inch to 13/16
inch. An optional attachment is available to increase this range to 1
3/16 inches. Lip-height tolerance is 0.001 inch, which exceeds National
Aerospace
Standards.

Optional fixtures sharpen other cutting tools such as step drill
bits, brad points, 90-degree points, large drill bits and single-flute
countersinks. The machine also features left-hand drill capabilities as
well as cams for 3- and 6-flute countersinks. All sharpener adjustments
and attachment changes are performed without tools. A lock-and-pin
system secures the attachments. The device’s solid metal design
includes steel and bearing-grade bronze components in all critical
places, and roller bearings are incorporated in areas where wear might
occur.

The sharpener is available with a choice of CBN
Borazon wheels, which are recommended for high speed steel and cobalt
tools, or with diamond wheels, which are recommended for carbide
cutting tools. These super-abrasive wheels require no dressing, thereby
reducing grit. The sharpener is more than 90-percent enclosed and
includes a vacuum port that users can connect to a vacuum system to
ensure clean operation. It is also available with two different
vacuum-powered grit-removal systems. The ¼-horsepower, 3,450-rpm motor
is rated for continuous duty.

Rather than tossing dull bits into a basket and pulling newly
purchased bits from stock, operators can now sharpen the drills
themselves or use re-sharpened bits waiting in reserve. The Darex
machine has paid for itself many times over, but the ability to sharpen
drills in-house provided Dalton with more than just cost benefits. For
example, the company wasn’t always happy with the results of sending
tools out of the shop for sharpening. With the XT3000, however, it can
better ensure a quality job. According to Dalton Gear staff, the
re-sharpened drill bits are on-size and work as well as new ones.

Operators
also like the fact that the sharpener is easy to use—most people in the
shop intuitively understand how to operate it. Users can often begin
sharpening bits after only a brief demonstration. In addition, the
sharpener allows Dalton personnel to control each drill-bit point
configuration, including the relief and design of the split point. For
example, an ordinary jobber drill can be re-sharpened into a
high-performance split drill.

“In these tight economic
times, this machine has helped us control expenses by sharpening drills
in-house rather than sending them out for sharpening or buying new,”
Mr. Holler says. “These types of expenses come out of the profit of
what we are selling. The value of the Darex machine is that it
allows profits to stay where they need to be.”

Comments are reviewed by moderators before they appear to ensure they meet Modern Machine Shop’s submission guidelines.